This bit of research should make you smile (or maybe smirk).
Ernest L. Abel and Michael L. Kruger at Wayne State University have found that the larger your smile, the longer you may live. Yes, that's right; "smile intensity" seems to have a statistically significant effect on a person's longevity.
In their research, to be published in the journal Psychological Science, the professors conducted an amusing case study that used a sampling of 230 photographs of baseball players culled from the now-defunct Sporting News Baseball Register. The professional ball players were chosen as a representative sample because detailed life statistics (such as birth, death, education, marital status, etc.) were available for each, leading to a more conclusive study.
The players' headshots, taken in the lead-up to the 1952 season, were analyzed by the researchers and their assistants and given flat distinctions of either "no smile," "partial smile" or "full (Duchenne) smile." After some Web sleuthing, the researchers compiled the life data for the baseball players and controlled for body mass index, career length, marital status, college attendance and other longevity factors.
The results? Even a partial smile added years to a player's lifespan.
On average, the players with no smile lived for 72.9 years, a full two years less than those who exhibited partial smiles. Those with the largest grins reaped an even longer lifespan: Players with full smiles lived to 79.9 years, almost two years longer than the typical life expectancy for an American. That's an overall difference of seven years of life between those players that chose not to smile and those who gave wholehearted grins.
The researchers also ran the same study again and rated each of the players headshots based on a three-point scale of attractiveness. Unlike a player's smile, there was no significant correlation between a player's perceived attractiveness and their longevity.
But smiles, it seems, can be telling about our characteristics.
"Individuals whose underlying emotional disposition is reflected in voluntary or involuntary Duchenne smiles may be basically happier than those with less intense smiles and hence maybe more predisposed to benefit from the effects of positive emotionality," concluded the researchers.
Before you smirk and explain that there must be some other factor involved, it's worth mentioning that this study is not an anomaly. The researchers cited numerous other studies displaying the powerful effects of relatively simple facial expressions and emotional conditions like involuntary happiness or sadness.
Last year, widely published research by Matthew J. Hertenstein found that smile intensity in yearbook photographs could predict relatively accurately whether or not a person would later go through a divorce. In 2005, a study found that participants could predict the outcome of 70 percent of Senate congressional elections with just a split-second judgment of the facial appearance of the candidates. Related studies with controlled circumstances have found that facial appearance (and smiles or lack thereof) can also predict sexual orientation and socioeconomic status.
Much of the evidence, it appears, has been written all over our faces.
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